This application claims priority from Taiwan Patent Application No. 91200174 filed Jan. 9, 2002.
The invention relates to a tire-condition sensor of a pneumatic tire, and more particularly, to a tire-condition sensor, of a pneumatic tire, that is firmly attached to the wheel rim by the use of a valve hole of the tire.
There are many sensing apparatuses for monitoring tire pressure in the prior art for a pneumatic tire vehicle. For example, a U.S. Pat. No. 4,048,614 xe2x80x9cLow Tire Pressure Warning Devicexe2x80x9d granted to Shumway et al. on Sep. 13, 1977 discloses a tire-condition warning system that, being installed on the wheel rim, includes a wireless transmitter for actuating, a power source, a switch, and a diaphragm. The warning system can trigger the wireless transmitter to provide driver with warning signal when the tire pressure is lower than a predetermined pressure value. But the above-mentioned warning apparatus can only provide warning signal when the vehicle has excessive low tire pressure. Besides, the constituted members of the warning apparatus is rather complicated, thereby, the warning apparatus is not applicable to the modern vehicles.
Another U.S. Pat. No. 5,844,131 xe2x80x9cTire Pressure Sensor Apparatus for a Pneumatic Tire Vehiclexe2x80x9d granted to Gabelmann et al. on Dec. 1, 1998 discloses a tire pressure sensing apparatus. The sensing apparatus includes a housing having at least two base seat members for placing the apparatus on the wheel rim platform and adjustably supporting the housing to be fixed in place by acting together with a wheel valve rod.
Still another U.S. Pat. No. 6,055,855 xe2x80x9cTire Pressure Sensor Wheel Attachment Apparatusxe2x80x9d granted to Straub et al. on May 2, 2000 discloses an apparatus for fixing on the wheel rim of a vehicle. The apparatus possesses a pressure sensor fixing on the wheel rim by threaded connection with a tire valve rod.
In addition, U.S. patent application Ser. No. 09/910,725 filed on Jul. 24, 2001 (corresponding to Taiwan (R.O.C.) Patent application number 089,117,036 entitled xe2x80x9cA Method and an Apparatus for Monitoring Pneumatic Tire Pressurexe2x80x9d) discloses a sensor module, attached to a pneumatic tire, for sensing the tire pressure and transmitting the signals obtained from the tire pressure wirelessly. Moreover, U.S. patent application Ser. No. 09/941,567 filed on Aug. 30, 2001 (corresponding to Taiwan (R.O.C.) Patent application number 089,118,096 entitled xe2x80x9cTire Condition Sensor of Pneumatic Tire of a Vehiclexe2x80x9d) discloses a tire pressure sensor attached to a pneumatic tire. These two US applications are incorporated herein by reference in their entirety.
However, the sensor of the aforementioned prior arts is not able to attach firmly to the wheel rim of the tire, and the tire-condition sensor oftentimes drops while the vehicle bumps along an uneven road.
To resolve the above-mentioned problems, it becomes necessary to provide a wheel rim having the sensor firmly fixed in order that the tire condition can be monitored constantly and worked normally.
In the light of the above-mentioned disadvantages, an objective of the invention is to provide a tire-condition sensor that can be firmly fixed on the wheel rim of a wheel and can be interacted with a receiver in order to monitor the service condition of the tire.
Another objective of the invention is to provide a tire-condition sensor that has an antenna device disposed along the surface of the sensor for reducing the chances of damaging the antenna.
To attain the above-mentioned objectives, the invention provides a tire-condition sensor for installing on a wheel rim of a tire. The wheel rim defines a wheel rim platform and a valve rod. The tire-condition sensor includes a valve rod, a main body, and two positioning devices. The valve rod is for passing through the valve hole and being fixed on the wheel rim. The main body has a sensor for sensing the condition of the tire, connecting to the valve rod, and defining a positioning direction which is more or less perpendicular to the wheel rim platform. The two positioning devices, positioning on the main body, can move in the positioned direction relative to the main body, adjustably touch the wheel rim platform, and by means of this to firmly fix the tire-condition sensor.
In one aspect of the invention, the tire-condition sensor includes also an antenna disposed along an upper plane defined by the main body, an outer lid for protecting the antenna, and a multiplicity of slots for exposing the antenna.
In other aspect of the invention, the positioning device of the tire-condition sensor is the two-bolt. The main body has also two threaded holes each hole matches with one of two bolts respectively, thereby, it can adjustably touch the wheel rim platform of the wheel rim.
Still another aspect of the invention, the main body of the tire-condition sensor has also two protuberances at both sides thereof to protect the tire-condition sensor.
According to the above-mentioned statements, the tire-condition sensor of the invention has two adjustable bolts that act together with the valve rod so as to make the tire-condition sensor firmly fix to the wheel rim platform. Moreover, the tire-condition sensor includes also a low-profile antenna and the protuberances that can prevent the tire-condition sensor from being damaged by the tools while it is performed maintenance.
In order to make the foregoing and other objectives, characteristics, and advantages of the invention more significant and easy to understand, preferred embodiments with accompanied figures will be illustrated as follows: